Envelope



Jan; 2, 1940.

H.DAHLHAU$ ENVELOPE Filed Jan. 27, 1937 Patented Jan. 2, 1940 ENVELOPE Heinrich Dahlhaus, Wuppertal-Elberfeld,

Germany Application January 27, 1937, Serial No. 122,598 In Germany February 7, 1936 lzeiaims. ((1229-80) The present invention relates to a etter envelope, packet or the like, intended lrrincipally for dry sticking, i. e., capable of. being sealed without the application of moisture, by using self-gumming adhesive.

The envelopes of this kind known hitherto were usually made on the basic principle of providing the usual closure flap, and also the corresponding part of the surface of the bottom flap with self-gumming adhesive, so that the ordinary closure flap provided with dry adhesive was used for closing. the envelope.

In other known types of envelopes of this kind the dry adhesive was applied to different parts of the envelope or the usual closure flap. In these envelopes it is necessary when a letter is inserted or when the envelope is sealed up, to fold the adhesive-provided flap or flaps in such a way that the areas of dry adhesive lie together an and adhere together to effect closure of the envelope.

An object of. the present invention is an envelope in which the flaps provided with dry adhesive do not have to be folded over to enable 25 the letter to be inserted or the envelope sealed.

Another object of the invention is an envelope in which two strips or patches of dry adhesive are located opposite one another interiorly of theenvelope, with a non-adhesive flap lying in- 30 termed ate these strips or patches and adapted normally to prevent adherence between them.

Still another object of the invention is an envelope in which an ungummed flap is hingedly attached to one of the flaps carrying the dry 35 adhesive, whereby the ungummed flap can simply be folded back into the envelope by the insertion of a letter so as to cause the adhesive areas to come together and unite.

In another feature of the invention, the inter- 40 mediate flap is made sufliciently long to project out of the envelope, whereby the dry adhesivecarrying flap associated therewith can be pulled out of the envelope. 'I 'he letter is then slidden 45 into the envelope and rthe drawn-out flap bent over and pushed betvieen the letter and the other side of the envelope to bring the areas of dry adhesive into contact.

In order that the invention may be clearly Fig 2 shows the dry or self-gumming adhesive applied,

Fig. 3 shows the side flaps folded over, Fig. 4 shows the side flap provided with dry adhesive partly folded back on itself.

Fig. 5 shows the other side flap and the closure flap gummed, v

V, Fig. 6 shows the bottompanel folded over,

Fig. 7 shows the finished envelope, of which I Fig. 8 is a section,

Fig. 9 shows the letter being inserted,

Fig. 10 shows a modification with a projecting side fiap, which is being withdrawn,

Fig. 11 is a section of Fig. 10,

Fig. 12 shows the letter being inserted, and 15 Fig. 13 shows the closed envelope with the letter inside.

- The blank (Fig. 1) stamped or cut out of a web of paper has side flaps I and -2, bottom v panel-6 top panel liand closure flap 4. The side flap I is provided with a further flap Ia hingedly attached thereto. The outside of flap I and the shaded inside marginal portion of the bottom panel 6 are then provided with dry or selfgummingadhesive. When this,gum is dried the side flaps I and 2 are folded over (Fig. 3), and the flap la is folded back on fiapfl (Fig. 4). In Fig. 5 an ordinary adhesive has been applied to the side flap 2 and the closure flap 4, and-when the bottom panel 6 is folded over it adheres to the side flap 2 (Fig. 6), whilst when the closure flap 4 is folded over it adheres to the bottom panel 6 (Fig. 7) s0 thatthe envelopeis now ready for use. In this position the intermediate portion In prevents contact between the areas of 55 dry adhesive.

The fold or crease between the parts I and la is not made absolutely sharp, so thatthe front andrear sides of the envelope are pressed away from one another at this place (Fig. 8), the let- 40 ter 5 being introduced in the gap thus formed, (Fig. 9) Consequently the flap part la is pressed back to its initial position and it is now the turn of the letter to separate the areas of dry adhesive. After the letter has been well inserted the two patches of self-gumming adhesive come into contact with one another, the self-guznming action takes place, and the envelope is sealed.

Alternatively, the side flap la can be made somewhat longer than the flap I, so that a part do an it projects out of the folded envelope (Figs.

10 and 11) Before the letter is inserted this flap is pulled out and then the letter is inserted (fig. 12), after which the flaps land Ia are introduced between the letter and the back of the 56 envelope and the self-gumming action takes place (Fig. 13).

By providing the dry adhesive elsewhere than on the usual closure flap, great security against unauthorized opening of the envelope is achieved, thus preserving the secrecy of the letter. As the dry-sealed part is inside the envelope it is not apparent and it is in any event very difficult to open becausethere is nothing to get hold of. Not only does the folded-back side flap prevent the two patches of dry adhesive sticking together, but it also indicates clearly the place where the letter should be inserted, and the letter can be easily inserted by pushing back this fold. By this pushing back of the side flap on insertion of the letter, the self-sealing action is set up without trouble by pressing the flaps lightlytogether when the letter has been fully inserted. In the modificationin which the side flap is lengthened, the flap is easy to pull out of the envelope, the gumming taking place automatically after the letter has been inserted and the flap'pushed in.

It is of course obvious that instead of. using dry self-gumming adhesi e, the side flap may be gummed in the ordinary way. This gum must be dried before folding the envelope, and the flap has to be moistened to close the envelope. The envelope shown in the accompanying drawings is given merely by way of example, and other shapes existing in the art may be dealt with in the same way.

The terms dry adhesive and self-gumming adhesive used herein and in the appended claims are to be understood to refer to adhesive which forms a tight joint or closure without the necessity for applying moisture.

I declare that what I claim is:

1. An envelope having a front panel and a rear panel, one of said panels having thereon l. a patch of self-gumming adhesive, and an extension on the. other of said panels, said extension having a patch of self-gumming adhesive thereon and having an ungummed area, said patches of adhesive lying normally within the envelope and said ungummed area being adapted to separate saidpatches of adhesive.

2. An envelope having a front panel and a rear panel, one of said panels having thereon a patch of self-gumming adhesive, and an extension on the other of said panels, said extension having a patch of self-gumming adhesive thereon and having an ungummed area, normally separating said patches of adhesive but being adapted to be pushed back by the insertion of a letter between the said envelope panels and thus to permit the adhesive patches to contact with one another. I

3. An envelope adapted to be sealed by selfgumming adhesive, having a panel provided with a patch of self-gumming adhesive adapted to co-op-erate with a flap likewise provided with a patch of self -gumming adhesive, the two patches of adhesive being normally separated from one another by a further ungummed flap, adapted to be pushed back by the insertion of a letter into the envelope and thus to permit the adhesive patches to contact with one another.

4. An envelope adapted to be sealed by selfgumming adhesive, having a panel provided with a patch of self-gumming adhesive adapted to co-operate with a flap likewise provided with a patch of self-gumming adhesive, the two patches of adhesive being normally separated from one another by a further ungummed flap,

both of said patches of self-gumming adhesive being located interiorly of the envelope.

5. An envelope having a front panel and a rear panel, an extension flap hinged to one of, r I) width than the gummed strip, and the other of said panels being provided with a gummed strip adjacent the marginal edge thereof which is adjacent and parallel to the adhesive strip on the said extension flap.

6. An envelope adapted to be sealed by selfgumming adhesive comprising a top panel, bottom panel and two side flaps, one of said side flaps, and the adjacent marginal portion of said bottom panel being secured together by ordinary adhesive in the manufacture of the envelope, and the other side flap and the adjacent lateral edge of the bottom panel being provided with patches of self-gumming adhesive, the secondmentioned side flap being folded over on itself and being adapted normally to present a plain ungummed surface to the adjacent patch of selfgumming adhesive on the bottom flap, and being adapted to be flattened out again to permit interaction of said adhesive patches on the inser tion of a letter into the envelope.

7. An envelope according toclaim 6, wherein the side flap bearing the self-gumming adhesive is greater in width than the other side flap and is folded over at approximately the centre of its width so that no part of it projects beyond the side of the envelope.

8. An envelope adapted to be sealed by selfgumming adhesive, comprising a bottom panel, a top panel, a first side flap on said top panel, said first side flap being secured to the adjacent marginal portion of the bottom panel by ordinary adhesive, a second side flap hingedly connected to said top panel and greater in width than the first side flap, said second side flap being normally folded about a line parallel to its line of connection to the top panel and nearer to this line of connection than to the outer free edge of the second side flap so as 'to lie mainly within the envelope, a patch of selfgumming adhesive on the outer side of the second side flap and between its line of connection to the top panel and its irtermediate fold line, a patch of self-gumming adhesive on the adjacent lateral margin of the bottom panel, and normally separated by the ungummed outer portion of the second side fiap from the adhesive on the bottom panel, whereby on withdrawal of said second side flap from the envelope and subsequent insertion of a letter in the latter, the second side flap can be reversed and tucked into the envelope behind the letter to bring the two patches of self-gumming adhesive into contact.

9. An envelope in which the flap left free for sealing the envelope after the insertion of a letter is tucked into the interior of the envelope and is folded back on itself to form a further flap adapted to project out beyond the edge of the envelope, said further flap being arranged for complete withdrawal from the envelope and, after a letter has been inserted, to be tucked in at the back of the. letter and means for sealing said flap to the adjacent part of the envelope.

10. An envelope provided in manufacture with two panels, one bearing an area of Self-gumming adhesive and the other having a flap bearing a second area of self-gumming adhesive, such 'fiap being normally folded back inside the assembled envelope and having an ungummed portion lying between said adhesive areas whereby to prevent contact between them. v

11. An envelope having a front panel and a rear panel, one of said panels having thereon a patch of self-gnmming adhesive, and an extension on the other of said panels, 'said'extension having a patch of self-g'lmming adhesive thereon adjacent its connection to the panel to which it is attached and an ungummed area remote from the latter andadapted normally to separate said patches of adhesive.

12. An envelope formed from a blank having two panels integral with one another and adapted to form the front and back respectively of the envelope, one of these panels having an extension, or flap adaptedto be doubled back onto its panel and provided with a longitudinal folding crease between its attached and free ends, a strip of self-gumming adhesive on said extension or flap between its attached end and the said folding crease and a secondstrip of self-gumming adhesive on the other of these panels, whereby these strips are arranged end-to-end' and are aligned when the said extension or flap is doubled back onto its panel, and the blank being foldable along a line perpendicular to the lengths of said'adhesive strips to bring the said two panels into superposed relation and the adhesive strips into. opposed positions with the ungummed portion of the extension or flap between these strips.

HEINRICH DAHLHAUS. 

